misc. brake problems

[mike944]

I just replaced my entire braking system.
master cyl, stainless braided flex lines, rebuilt calipers, pads, rotors, even parking brake shoes.

2 problems i have:

1. under braking, sometimes the car pulls to the right, sometimes to the left. most of the time it goes straight though. I can't find any play in the suspension components. anyone have a clue what it might be? it could possibly be related to problem 2, but that wouldn't explain why sometimes it pulls right, and sometimes to the left.

2. my pedal is still a little spongy. that's why i put in stainless braided lines, and a new m/c, but there was no noticable improvement in pedal firmness. I think there may still be some air in the system. How do you get all the air out? any special tricks? I tried vacuum bleeding, pumping the pedal, and pressure bleeding at 3 psi. (an air fitting attached to a spare resevoir cap) I didn't want to up the pressure any more for fear that the resevoir would fly off, and spray brake fluid everywhere.

Just for reference, I am using Catrol LMA fluid

Thanks,
Mike

p.s. both problems existed before the rebuild, which is why i did it. I thought it might be a partially siezed caliper. It used to pull only to the left, and the left wheel would lock before the right.

[1.2gees]

I think your problem of "sometimes right, sometimes left" is becaus of traction/level differances between the two sides of the car.

I suggest you go to an empty, level, and CLEAN parking lot, and try hard braking, see if you get any pull. I say the parking lot should be clean, cause a little sand forexample would change things a bit.

It's highly probably you've gotten air in the system, but I would (and do) use the normal two person procedure instead. However some dealers used a pressure pump, so it should be ok. I don't think 3psi is enough to pop the reservoir out, but hey, if it does, you can just put it back in, it was made for that!

I believe you're supposed to bleed the rear calipers with the front of the car higher than the rear, it might be the otherway around, but I'm fairly sure...

BTW, I recommend ATE Super Blue Racing brake fluid, it's the best I've tried so far, but Castrol isn't that bad... This is REGULAR DOT 4 we're talking about right?

BTW, what year is your car, NA? Turbo? S2?

I think this helps a bit, let me know...
Good luck,
Ahmet

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It's all the driver...

[Pilot_951S]

1.2 is right, if the surface is uneven sometimes you will get a pulling either right or left. When the nose dives under braking the front suspension has a small problem maintaining the correct toe settings, so if the surface is uneven the car pulls.

To frix the mushy pedal I would try two things : (in this order)

1) change out whatever pads you have in the car for a good stiff high performance pad (may favorite so far are Performance Friction Carbon Metallic Z Rated Street pads). The stock pads are soft and they compress under load causing mushy pedal feel.

2) Adjust the brake pedal free play at the pedal assembly. There should be a locking nut on the rod that goes from the pedal through the firewall to the vaccumm booster. This rod should be able to turn for adjustment. You want to turn it so more rod goes into the booster.

[This message has been edited by Pilot_951S (edited 08-07-2000).]

[todd951]

1.2gees mentioned elevating one end of the car when bleeding the rear brakes, but he got it backward. You want to elevate the rear of the car. Air bubbles are going to tend to rise, so you want the bleeder screw on the caliper to be the highest point so that the air bubbles will be forced out.

[mike944]

i'll try to elevate the rear when i bleed them this weekend, as far as the possibility of the pulling being related to the surface of the street, i think that might be it. When i was driving today, it pulled to the right really hard once, and i happened to notice that the right wheels were in a depression in the road. oh well, i guess there's not much i can do about that !

i'll let you know if elevating the rear of the car solves the spongy pedal problem.

Mike